1. Field of the Invention
The present invention relates to an attachment device for a suspended member, for example, an attachment device regarding a display apparatus having a large screen formed by arranging a plurality of thin display devices with multi-tiling.
2. Description of the Background Art
There is a large-screen display apparatus in which a plurality of display devices is arranged with multi-tiling (that is, aligned in the vertical and horizontal directions) and all these display devices are regarded as one screen. Conventionally, a rear projection projector capable of displaying an image even in an end of a screen is mainly adopted as the individual display devices. However, in recent years, even in a thin display apparatus represented by a liquid crystal display, a narrow bezel type thin display device specialized for the multi-tiling has been developed to be a product.
Since such a thin display device has small thickness unlike the rear projection projector, the thin display device can be installed while being attached to a wall surface. For example, Japanese Patent Application Laid-Open Nos. 2003-15541 and 2006-53212 describe a wall-hanging device for attaching a thin display to a wall surface. In more detail, Japanese Patent Application Laid-Open No. 2003-15541 describes a technology of moving a display device in the left and right direction from a state that the display device is in contact with an attachment member in the up and down direction, fitting the display device and the attachment member to each other when reaching a proper positional relationship, and thereby fixing the display device to the attachment member, and a technology of providing a tilt mechanism. Japanese Patent Application Laid-Open No. 2006-53212 discloses a wall-hanging device easily attachable to and detachable from a wall surface.
FIGS. 27 and 28 show one schematic example of a large-screen display apparatus obtained by arranging a plurality of display devices with multi-tiling. FIG. 27 is a front view of the large-screen display apparatus, and FIG. 28 is a side view of the large-screen display apparatus. In the example of FIGS. 27 and 28, four display devices 100a to 100d are arranged two by two.
However, when the display devices 100a to 100d are attached to the wall surface with adopting the wall-hanging device described in Japanese Patent Application Laid-Open Nos. 2003-15541 and 2006-53212, there is a possibility that the display devices 100a to 100d are not arranged in proper posture and at proper positions relative to each other.
FIG. 29 is an enlarged view showing a region A including all the four display devices 100a to 100d (also refer to FIG. 27). FIG. 30 is an enlarged view showing a region B including both the two display devices 100a and 100b (or 100c and 100d) arranged in the up and down direction (also refer to FIG. 28). In the example of FIG. 29, the display device 100c on the upper right side is displaced in the upper right direction from the proper position, and a gap is generated between the display device 100c and the adjacent display devices 100a and 100d. Furthermore, when seen from the front side, the display device 100c is arranged while being tilted relative to the display devices 100a, 100d. In a case where the display device 100c is arranged in such a way, a portion where an image is missing is broadened between the display device 100c and the display devices 100a and 100d. 
In the example of FIG. 30, the upper display device 100a (or 100c) is displaced forward (in one direction perpendicular to a screen) relative to the lower display device 100b (or 100d). In a case where the display device 100c is arranged in such a way, the portion where the image is missing is broadened when the screen is seen from the oblique directions D1 and D2, for example. This is because an upper portion of the display device 100b is hidden by the display device 100a when seen from the direction D1, and the portion where the image is missing is generated between the display devices 100a and 100b when seen from the direction D2.
As described above, in a case where the display devices 100a to 100d are not arranged in the proper posture and at the proper positions relative to each other, quality of the image is lowered. Appearance quality and an aesthetic property of the large-screen display apparatus are also deteriorated.